The present invention relates to the sealing art, and more particularly, to devices of the type in which a member is in threaded engagement with a threaded opening formed in a housing which contains fluid, which must be retained within the housing.
Although the sealing arrangement of the present invention is adapted for use in many types of devices, it is especially suited for use with mechanical devices such as vehicle transmissions, and will be described in connection therewith. On vehicle transmissions, there is frequently a need to install a threaded member, such as a speedometer sensor, into threaded engagement with the housing of the transmission. If the device contains fluid, such as water or lubricant oil, it is necessary to provide a sealing arrangement around the threaded member, in order to prevent leakage of the fluid from within the housing of the device to the exterior thereof. The invention is applicable to devices wherein the fluid within the housing is at substantially atmospheric pressure, as well as to devices wherein the fluid is typically at a positive pressure.
In some such applications, any one of a number of well known gasket designs may be sufficient, but in various other applications, the use of a gasket is not practical. As is well known to those skilled in the art, a typical gasket design requires that there be a fairly large clamping or sealing area between two members. Therefore, the present invention is especially suited for applications in which the member being sealed (e.g., a threaded speedometer sensor) does not provide sufficient clamping area between itself and the adjacent member (e.g., the transmission housing) to permit the use of a conventional gasket assembly.
In such applications, it has been conventional to install an O-ring at the junction of the threaded portion and the head of the threaded member, such that the O-ring remains with that particular threaded member. In some applications, the use of such an O-ring is acceptable, but in various other applications, where the threaded member is occasionally replaced, the use of an O-ring which remains with the threaded member is not acceptable, because if the O-ring is not transferred to the replacement threaded member, or a new O-ring is not provided with the new threaded member, the result will be a loss of satisfactory sealing.